WASHINGTON — Al-Qaida is using U.S.-led coalition airstrikes in Syria as a reason to extend olive branches to the renegade Islamic State group, saying the two should stop feuding and join forces to attack Western targets — a reunification that intelligence analysts said would allow al-Qaida to capitalize on the younger group’s ruthless advance across the region.

Analysts are closely watching al-Qaida’s repeated overtures, and while a full reconciliation is not expected soon — if ever — there is evidence the two groups have curtailed their infighting and are cooperating on the Syrian battlefield, according to activists on the ground, U.S. officials and experts who monitor jihadi messages.

Al-Qaida is saying, “Let’s just have a truce in Syria,” said Tom Joscelyn, who tracks terror groups for the Long War Journal. “That is what’s underway now. … What we have seen is that local commanders are entering into local truces. There are definitely areas where the two groups are not fighting.”

The Islamic State group has seized about a third of Iraq and Syrian territory and is terrorizing civilians to impose a strict interpretation of Islamic law. Their advances led to airstrikes by the United States and a coalition of Western and Persian Gulf nations in both Iraq and Syria.

IS was kicked out of al-Qaida in May after disobeying its leader, Ayman al-Zawahiri. So far, IS has not publicly responded to al-Qaida’s calls to reunite — the most recent on Oct. 17 from al-Qaida in the Arabian Peninsula, the Yemen-based offshoot that denounced the airstrikes and called on rival militant groups to stop their infighting and together train their sights on the West.